We had contractors in our home and gave them a key and it was a total NIGHTMARE. The GC was supposed to be on site at all times when the subs were here. That didn't happen.
My daughter caught one of the 'employees' sneaking onto the main level of the house (She was in her twenties and they had no idea she was home). He walked right up the stairs - he turned the corner and ran into her. He muttered something about wanting to light his cigarette on the stove

We were fairly certain he was up to something else. He was killed in a drug deal gone bad less than a week later. Two of the other workers were witnesses and fled.
The subs did subpar work if the GC wasn't around to supervise (and sometimes even if they were there).
This was a company that came highly recommended to us as well. Never again......